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High Blood Pressure: Checking Your Blood Pressure at Home

Introduction

When blood pressure is high, it
starts to damage the blood vessels, heart, and kidneys. This can lead to
heart attack,
stroke,
kidney disease, and other problems. But if you don't measure your blood pressure, you won't know when it's high, because there are
usually no symptoms.

If you are a
healthy adult with normal blood pressure (119/79 or below), have
your blood pressure checked at least every 1 to 2
years.1

If your systolic blood
pressure (the first number) is 120 to 139
and/or your diastolic blood pressure (the second number) is
80 to 89, you are prehypertensive.
This means that your blood pressure is higher than normal but not high enough
to be high blood pressure. It is a warning that your blood pressure is going
up. If you are in this category, you should have your blood pressure
checked as often as your doctor advises, or at
least once a year.

Adults with other
risk factors for heart disease or evidence of disease caused by high blood
pressure need to have their blood pressure checked more often.

A home blood pressure monitor makes it easy to keep
track of your blood pressure.

Blood pressure is a measure of how hard the blood pushes
against the walls of your arteries as it moves through your body. It's normal
for blood pressure to go up and down throughout the day, but if it stays up,
you have high blood pressure.

For your doctor
to confirm that you have high blood pressure, your blood pressure must be at
least 140/90 on three or more separate occasions. It is usually measured 1 to 2
weeks apart.

Measuring blood pressure

A blood pressure cuff is inflated around
your upper arm. This stops the blood from flowing through the artery in your
arm.

The cuff is slowly deflated. A stethoscope placed on the
inside of your elbow picks up the sound of the blood beginning to flow through
the artery again.

As the cuff deflates even more, the sound
eventually stops.

Blood pressure is recorded as two measurements:

Systolic pressure: This is the reading on the gauge when blood flow is
first heard. It's the highest pressure that occurs when your heart
muscles contract.

Diastolic pressure: This is the reading on the gauge when blood flow
can no longer be heard. It's the lowest pressure that
occurs when your heart relaxes between beats.

Blood pressures are measured in
millimeters of mercury (mm Hg). Systolic pressure, the higher of the two
readings, is measured first. Diastolic pressure is the lower reading. For
example, if your systolic pressure is 120 mm Hg and your diastolic pressure is
80 mm Hg, your blood pressure is recorded as 120/80, or
"120 over 80."

Test Your Knowledge

Many people who have high blood pressure don't know
it, because it usually has no symptoms.

See if you have low
blood pressure that may be caused by irregular heart rhythms, certain
medicines, or other medical conditions.

Make sure that
any medicines you take for other problems are not causing episodes
of high blood pressure.

When you have high blood pressure, taking your
own measurements can help you see how medicine
or lifestyle changes are helping to lower your blood pressure.
It can help you feel more involved in and more
in control of your own health care.

Some
people have a big rise in blood
pressure only when they are in a doctor's office. This is called "white-coat
hypertension." It probably is caused by worry about the
doctor visit. By checking blood pressure at home, these
people can often find out whether their blood pressure readings generally are
lower when they are not in the doctor's office.

Test Your Knowledge

If I take my blood pressure at
home, I can help my doctor decide
whether I have high blood pressure and what effect my
medicines have.

Blood pressure devices

Manual devices. This is the kind of device you usually see at the doctor's office. It
involves using a stethoscope to listen to the heartbeat.

Electronic (digital) devices. These are easier to use. They do the listening for you.

When you first get a blood pressure
device, check its accuracy. Do this by comparing
its readings with those you get at
the doctor's office. Ask your doctor or nurse to watch you
use your device to make sure that you are doing it right
and that it works right. It's a good idea to
have your device checked every year at the doctor's office.

The size of the
blood pressure cuff and where you place it can greatly
affect how accurate your device is. If the cuff is
too small or
too large, the results won't be right. You may have to measure your arm and choose a monitor that comes in the right size.

Measure blood pressure in your arm. Blood pressure monitors used on the wrist aren't as reliable as those that use arm cuffs. Wrist monitors should be used only by people who can't use arm cuffs for physical reasons. And devices that use finger monitors aren't recommended at all.2

Getting
ready

Before you take your blood pressure:

Don't eat,
smoke, or exercise for at least 30 minutes before
you take your blood pressure. And don't use any medicines
that can raise blood pressure, such as certain nasal sprays.

Rest
at least 5 minutes before you take a
reading.
Sit in a comfortable, relaxed
position with both feet on the floor. Don't move or talk while you are measuring your
blood pressure.

Try not to take your blood
pressure if you are nervous or upset.

If you can,
use the same arm for every reading. Readings may be 10 to 20 mm Hg
different between your right arm and your left arm.

Remember that blood pressure readings
vary throughout the day. They usually are highest in the morning after you wake
up and move around. They decrease throughout the day and
are lowest in the evening.

Using an electronic (digital) blood
pressure monitor

Sit with your arm slightly bent and
resting comfortably on a table so that your upper arm is on the same level as
your heart.

Wrap the blood pressure cuff around your bare upper
arm. The lower edge of the cuff should be about
1 inch (2.5 cm) above the bend of your elbow.

Press the on/off
button.

Wait until the ready-to-measure "heart" symbol appears next
to zero in the display window.

Press the start button. The cuff
will inflate.

After a few seconds, the cuff
will begin to deflate. The numbers on the screen will begin to drop.

When the measurement is complete, the heart symbol stops flashing.
The numbers tell you your blood pressure and pulse.

Using a manual blood pressure monitor

Sit with your arm slightly bent and
resting comfortably on a table so that your upper arm is on the same level as
your heart.

Wrap the blood pressure cuff around your bare upper
arm. The lower edge of the cuff should be about
1 inch (2.5 cm) above the bend of your elbow.

Close the valve on the rubber
inflating bulb. Squeeze the bulb rapidly with your opposite hand to inflate the
cuff. Keep squeezing until the dial or column of mercury
reads about 30 mm Hg higher than your usual
systolic pressure. (If you don't know your usual
pressure, inflate the cuff to 210 mm Hg.) The pressure in the cuff will
temporarily stop all blood flow in your
arm.

Put the stethoscope over the
large artery slightly above the inside of your elbow. You can find
this artery by feeling for its pulse with the fingers of your other
hand. If you are using a cuff with a built-in stethoscope, be sure the part of
the cuff with the stethoscope is over the artery.

Open the valve
on the bulb just slightly. The numbers on the
pressure dial or mercury tube should fall gradually—about 2 to 3 mm
Hg per second. Some devices automatically control the fall at this rate.

Listen through the stethoscope. As you watch
the pressure slowly fall, note the number on the dial or
tube when you first start to hear a pulsing or tapping sound. The sound is caused by the blood starting to
move through the closed artery. This is your systolic blood pressure.

Continue letting the air out slowly. The sounds
will become muffled and finally will disappear. Note the
number when the sounds completely disappear. This is your diastolic blood pressure. Finally, let out all the remaining air to take
the cuff off.

Keep a blood pressure
diary

Everyone's blood pressure
changes from day to day and even from minute to minute sometimes. So taking
your own blood pressure works best when you also keep
a diary.

Also write down any medicine you take and
what time you take it. Record anything that causes you
stress. These records can help your doctor
make sure you get the right treatment.

Blood pressure
tips

Don't let the
stethoscope rub on the cuff or your clothing. This may cause noises that make
your pulse hard to hear.

If you're not familiar with
using a stethoscope, you may want to get help from
someone who is. The accuracy of a blood
pressure recording depends on putting the stethoscope
in just the right place.

In the
beginning, always take your blood pressure 3 times. Wait 1 to 2
minutes between recordings to let the blood flow back into
your arm. After you get better at doing it, you
probably will need to do it only once or twice
each time.

Check your blood
pressure cuff often. Make sure the rubber tubing, bulb,
valves, and cuff are in good condition. Even a small hole or crack in the
tubing can lead to inaccurate results.

Take your monitor to your doctor's office once a year to have it checked.

You may not be able to use a
manual blood pressure monitor if you have poor hearing or eyesight or
if you can't move your hands and fingers easily. For
people with these limitations, an electronic arm- or wrist-cuff model is
better.

You may not be able to use an arm-cuff monitor if your arms are very large. If that is the case, have your doctor check your blood pressure regularly. An accurate blood pressure measurement is very important when you are very overweight, so don't rely on a wrist-cuff model.

Test Your Knowledge

The size and position of the blood pressure cuff can
affect the reading. I should check my blood pressure while I am seated in a
comfortable position.

The size and position of the blood pressure
cuff can affect the blood pressure reading. It is important that the cuff fits
right and is placed on the widest part of the upper arm. Check your blood
pressure while you are seated in a comfortable
position.

The size and position of the blood pressure
cuff can affect the blood pressure reading. It is important that the cuff fits
right and is placed on the widest part of the upper arm. Check your blood
pressure while you are seated in a comfortable
position.

Talk with your doctor

If you have questions about this information,
print it out and take it with you when you visit your
doctor. You may want to use a highlighter to mark areas or make notes in the
margins of the pages where you have questions.

If you would like more information on high blood pressure, the
following resources are available:

Organizations

American Heart Association (AHA)

7272 Greenville Avenue

Dallas, TX 75231

Phone:

1-800-AHA-USA1 (1-800-242-8721)

Web Address:

www.heart.org

Visit the American Heart Association (AHA) website for information on
physical activity, diet, and various heart-related conditions. You can search for information on heart disease and stroke, share information with friends and family, and use tools to help you make heart-healthy goals and plans. Contact the AHA to find your
nearest local or state AHA group. The AHA provides brochures and information
about support groups and community programs, including Mended Hearts, a
nationwide organization whose members visit people with heart problems and
provide information and support.

CardioSmart

Web Address:

www.cardiosmart.org

CardioSmart is an online education and support program that can be your partner in heart health. This website engages, informs, and empowers people to take part in their own care and to work well with their health care teams. It has tools and resources to help you prevent, treat, and/or manage heart diseases.

You can set health and wellness goals and track your progress with online tools. You can track your weight, waist measurement, blood pressure, and activity. You can use calculators to help you find your body mass index (BMI) and check your risk for heart problems. You can search for a cardiologist. And you can find medicine information and prepare for your next appointment. Also, you can join online communities to connect with peers and take heart-healthy challenges.

CardioSmart was designed by cardiovascular professionals at the American College of Cardiology, a nonprofit medical society. Members include doctors, nurses, and surgeons.

National Heart, Lung, and Blood Institute
(NHLBI)

P.O. Box 30105

Bethesda, MD 20824-0105

Phone:

(301) 592-8573

Fax:

(240) 629-3246

TDD:

(240) 629-3255

Email:

nhlbiinfo@nhlbi.nih.gov

Web Address:

www.nhlbi.nih.gov

The U.S. National Heart, Lung, and Blood Institute
(NHLBI) information center offers information and publications about preventing
and treating:

References

Citations

Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (2003). Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure JNC Express (NIH Publication No. 03–5233). Bethesda, MD: U.S. Department of Health and Human Services.

Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (2003). Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure JNC Express (NIH Publication No. 03–5233). Bethesda, MD: U.S. Department of Health and Human Services.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use.